Projectile for guiding and tensioning filling yarn



Get. 8, 1968 w, wu 3,404,708

PROJECTILE FOR GUIDING AND TENSIONING FILLING YARN Filed Sept. 15, 1967 F I G 4 220 24 0 26a 24o llllllllllIlllllImfllmlillmmgijmm!!! A 32 3| 30 3 32 F l G. 5 22 32 24b 26b 24b k2 22131315 521522 :'23f'2ti22229Y932t2 INVENTOR KARL W. WUEGER ATTORNEY United States Patent 3,404,708 PROJECTILE FOR GUIDING AND TENSIONING FILLING YARN Karl Willi Wueger, Spencer, Mass, assignor to Crompton & Knowles Corporation, Worcester, Mass., a corporation of Massachusetts Filed Sept. 13, 1967, Ser. No. 667,456 9 Claims. (Cl. 139-125) ABSTRACT OF THE DISCLOSURE A projectile for guiding and tensioning a filling yarn in pneumatic looms using a stationary filling supply. This projectile has a spiral yarn passageway located within its hollow body to permit a yarn to be freely blown therethrough and to apply a tension to a filling yarn drawn therethrough.

This invention relates to projectiles for use in looms wherein the filling yarn is drawn from a stationary supply and guided through a shed formed by warp yarns by means of a projectile or shuttle, such as that fully disclosed in my US. patent applications, Ser. Nos. 555,895 and 555,896, both of which were filed June 7, 1966. Pneumatic looms of this type use a combination system for inserting filling yarn into the warp shed. This combination comprises means whereby the filling yarn is at least partially blown through a projectile into the shed and then the projectile is propelled through the shed with the yarn moving relatively to the projectile while assisting its insertion. Thus, the projectile assists in the insertion of the yarn into the shed and adds enough tension to straighten out the kinks in the yarn that would be present due to simply blowing the yarn into the shed. The use of this combined weft insertion means enables much wider fabrics to be woven than is possible with the use of air jets alone. Yet applicants projectile is more easily loaded with the yarn than are the gripper type projectiles used in other conventional looms.

To be useful in this type loom however, the projectile must be constructed so that the yarn can be freely blown through it and yet the projectile must have the capability of tensioning the yarn as the projectile moves through the shed and the yarn is drawn through the projectile during its flight. In the above-identified applications the projectile was provided with clamping means in its interior which were opened by mechanical means during the blowing of the yarn therethrough and the clamps closed upon the yarn once the projectile was started into its flight to tension the yarn. This type of projectile has several drawbacks. The first of these drawbacks resides in the fact that the clamp must be spring loaded and that continual flexing of the springs results in eventual failure of the clamping means and, thus, of the entire projectile. Another drawback is that the clamping means in such projectiles must be varied for different yarn sizes in order to obtain a uniform tensioning of the yarn as it is being drawn through the projectile.

It is an object of this invention to provide a projectile wherein a filling yarn can be freely blown through its interior but cannot be drawn therethrough without the application of tension to the yarn.

It is a more specific object of the invention to provide a projectile that will apply substantially uniform tension to yarns of differing sizes.

These objects are accomplished by the provision of a projectile which has an elongated hollow body which contains an internal yarn passageway which is formed into a spiral within the hollow body of the projectile and thus causes the yarn to move in a spiral through the body. It has been found that the filling yarns can be freely blown ice through this body without any interference between the yarn and the surfaces of the internal passageway. However, as soon as the yarn is attempted to be drawn or pulled through this passageway, it comes into contact with the inner surfaces of the spiral passageway and the friction between the yarn the surfaces will apply the desired tension of the yarn. The amount of tensioning applied depends upon the number of pulls or spirals the internal passageway has within the body of the projectile.

The invention, and additional objects and advantages thereof, will best be understood from the following description thereof when read in conjunction with the accompanying drawings in which:

FIGURE 1 is a diagrammatic partial cross sectional illustration of the projectile showing the body in section and the internal yarn passageway in full;

FIGURE 2 is an illustration taken along line 2--2 of FIGURE 1 showing a cross section of the projectile;

FIGURE 3 illustrates diagrammatically a method of producing the spiral internal yarn passageway;

FIGURE 4 illustrates another method of producing the spiral internal yarn passageway; and

FIGURE 5 illustrates a third method of producing the spiral internal yarn passageway.

Referring more particularly now to FIGURES 1 and 2 of the drawings, 10 designates the projectile which cornprises a hollow body 12. Hollow body 12 has a hollow intermediate cylindrical section 14 and hollow nose p l' tions 16 and 16 on the ends thereof. Hollow nose portions 16 and 16' have reduced portions 18 and 18 which fit into the ends of the cylindrical portion 14. Nose p rtions 16 and 16' also have hollow passageway receiving barrel portions 20 and 20' for receiving the straight sections 24 and 24' of a spiral internal yarn passageway 22. Internal yarn passageway 22 has one or more coils in a spiral section 26. The outer diameter of the coils are such as to fit within the hollow cylindrical section 14. Internal yarn passageway 22 is hollow and has openings 28 and 28 at the ends of its straight sections.

The projectile is assembled by placing the spiral section of the yarn passageway into the hollow cylindrical section 14 of body 12. Once this passageway is in place it is connected as by cementing or bonding to the internal surface of section 14. When this has been accomplished, nose portions 16 and 16' are placed into the position shown in FIGURE 1 and similarly connected to the internal yarn passageway and the cylindrical section of body 12. It is to be appreciated that, while FIGURE 1 shows but a single coil, in the spiral section, this section can contain a plurality of coils, and the number and pitch of the coils will be determined by the amount of tension that is deemed desirable on the yarns during the drawing of the filling yarn therethrough. The greater the number of coils, and/or the smaller their pitch, the more tension will be applied to such yarn as it is drawn therethrough.

Referring now to FIGURE 3 there is illustrated one method of producing the internal yarn passageway used in the projectile shown in FIGURE 1. In this method a tubular material, such as steel tubing, is wound about a mandrel 30. Mandrel 30 is provided with grooves 31 and 31 for the reception of straight sections 24 of this internal yarn passageway 22 so that these portions may be aligned with the center of the coiled or spiral section 26. Mandrel 30 is of a diameter selected to give the desired outer diameter of the spiral section 26 of the internal yarn passageway.

FIGURE 4 is very similar to FIGURE 3 and uses the same mandrel. However, instead of using steel tubing, such as that shown in FIGURE 3, a finely coiled spring member is provided with a filler 32. The spring member is then wound about mandrel '30 in the fashion noted in regard to FIGURE 3 and the complete assembly is then impregnated with a resin which hardens upon application of heat such as phenol-formaldehyde. Filler 32 can be a material that is easily dissolved by chemical action or one that is destroyed by the heat used to set the thermosetting resin, provided that its melting point is higher than the setting temperature and less than the degradation temperature of the resin used. After the member 22a has been impregnated with the resin, filler 32 keeps the resin from. closing the passageway through the center of the coils. of the spring. Thermosetting resins such as phenol-formaldehyde have been found to be par ticularly useful in this form of the invention. After the resin has been cured and the filler 32 removed, member 22a will be ready for incorporation in the projectile as shown in FIGURE 1.

FIGURE 5 is very similar to FIGURES 3 and 4, but, instead of using the steel tubing or the finely coiled spring of FIGURES 3 and 4, it utilizes a finely braided wire mesh tube which is kept open by filler 32 while the tubing is wound about mandrel 30' in the fashion noted in regard to FIGURE 4 and the complete assembly is then impregnated with resin in the manner noted with regard to the embodiment of FIGURE 4. The resin is then cured and the filler 32 removed in the manner described above to provide the spiral internal yarn passageway 221).

While several methods of producing the internal yarn passageway have been illustrated and described above, it is to be appreciated by those skilled in the art that conventional methods of forming such tubing can be used and that the invention is not limited to the techniques described and illustrated. While specific terms have been used to describe the invention, it is to be understood that these terms are used in a generic and descriptive I sense only and not for purposes of limitation. The scope of the invention being deemed that of the appended claims.

What is claimed is:

1. A projectile for guiding and tensioning a filling yarn 4 in a pneumatic loom having a stationary filling supply, said projectile comprising:

(a) an elongated hollow body; and

(b) stationary means located within said hollow body which permit a filling yarn to be blown through said body substantially without tension and which applies a tension to a filling yarn being drawn through said body.

2. A projectile as set forth in claim 1 wherein said means comprises an internal yarn passageway, a portion of which is formed into a spiral configuration.

3. A projectile as set forth in claim 2 wherein said spiral portion of said yarn passageway is intermediate straight portions whose longitudinal axes are substantially parallel to the longitudinal axis of said hollow body.

4. A projectile as set forth in claim 2 wherein said spiral portion comprises at least one complete coil.

5. A projectile as set forth in claim 2 wherein said yarn passageway is constructed from steel tubing.

6. A projectile as set forth in claim 2 wherein said yarn passageway is constructed from a finely braided wire tube impregnated with a resin.

7. A projectile as set forth in claim 2 wherein said passageway is constructed from a fine wire coil impregnated with a resin.

8. A projectile as set forth in claim 6 wherein the braided tube is impregnated with a thermosetting resin.

9. A projectile as set forth in claim 7 wherein the wire coil is impregnated with a thermosetting resin.

References Cited UNITED STATES PATENTS 2,902,058 9/1959 Walton 139l26 2,955,409 10/1960 Speakman 57-345 3,256,914 6/1966 Hortmann l39125 FOREIGN PATENTS 1,440,165 4/1966 France.

HENRY S. JAUDON, Primary Examiner. 

